Sound engineers focus on delivering high quality sounds to human ears. Human ears perceive certain frequencies as being louder than others, despite having the same or even more energy behind those frequencies. The frequency range of sounds perceivable to human ears is around 20-20,000 Hz; the closer those boundaries are approached or exceeded, the softer the sound is perceived. Room and automobile interiors, arenas, stadiums and other open spaces, as well as speakers and other sound reproducing devices (including headphones) come in countless shapes, sizes, and configurations. The same note from the same instrument can sound different to human ears depending upon the environment and equipment with which the sound is being reproduced.
Tone controls (usually designated as the bass and treble controls or knobs) are simple filters included in most audio equipment for gross adjustment of the frequency balance. The bass control can be used, for instance, to increase the prominence of the lower frequency bass and drum parts of a song, or to reduce unpleasant bass sounds when listening to a person speaking. The treble control can be used to give the higher frequency percussion and vocal parts of a song a sharper or more brilliant sound, or to decrease the prominence of higher frequencies that might have been overemphasized in a song, all based upon the preferences of the listener.
Equalizers are software or hardware filters that adjust the volume or loudness of specific audible sound frequencies. Equalizers work in frequency ranges or bands, adjusting the amplitude of audio signals at particular frequencies. The treble and bass controls discussed in the previous paragraph are dual-band equalizers, providing the ability to adjust (cut and boost) the high and low frequency ranges, respectively. Higher quality sound systems can have three bands (providing a mid-range band in addition to treble and bass), five bands (three mid-range bands between treble and bass), and even twelve bands (even more mid-range frequency gradations between treble and bass). The greater the number of bands, the more divisions in the wide range of human hearing. Each band thus corresponds to a discrete range of frequencies, thereby allowing more control over the sound delivered at those frequencies. Professional sound engineers typically employ recording equipment with 20-30 or more frequency bands.
In music production and recording, equalizers are used to adjust the timbre and tone of individual instruments by their frequency content, to make certain instruments or voices more prominent, and to generally fit individual instruments and voices within the overall frequency spectrum of the sound mix. Equalization can also be used to reduce or eliminate unwanted sounds in a sound recording, such as hiss or other distortion, or to alleviate feedback (howling) in a public address system.
Equalizer settings are most often associated with particular genres of music. For a Rhythm and Blues style song, a slight dip in the mid-range frequencies will increase the prominence of the bass and the singing. Listeners of Rock genres often prefer a dip in the treble frequencies so that bass guitars and standard mid-range guitars are heard more prominently. For Voice and Pop genres, listeners typically prefer to emphasize the middle and treble ranges, leaving the lower frequency and bass ranges on a less prominent setting.
Graphic equalizers (abbreviated EQs) are often included in consumer audio equipment and software, which play on speakers (or headphones) music signals delivered from consumer devices such as smart phones, iPods, digital tablets, personal computers, disc players, radios, record turntables and the like. An EQ allows the listener to selectively adjust the amplitude of specific frequency ranges without changing the amplitude of other frequency ranges. An EQ display typically includes a digital image of sliders, each of which controls the volume of a certain frequency range of sounds. The bass and treble sliders adjust the amplitude of frequencies that are below and above a certain level, respectively. Each of the sliders in the middle has a range that controls the volume of sound frequencies between a lower limit and an upper limit. The sliders are typically arranged in a row on a control panel display, with the bass slider on the left, the treble slider on the right, and the mid-range sliders in the middle. When arranged horizontally, moving the sliders vertically increases the amplitude of the signal within their particular frequency range.
FIGS. 1A-1F illustrate examples of digital EQs as presented on the screen or display of a digital device, such as a smart phones, iPod, digital tablet or iPad, laptop or desktop computer, from which music and other sounds can be produced and delivered to a sound reproducing device, such as speakers or headphones. FIG. 1A represent a Flat EQ setting, in which all of the frequency range sliders are set in the zero position, no one slider, and hence no one frequency range having an amplitude any greater or less than another. FIG. 1B represents a Manual EQ setting, in which the sliders that control the amplitude of each frequency range are set differently with respect to the zero (or flat) position, according to the preferences of the listener. As shown, the sliders above the flat position are the frequency ranges being boosted (given more amplitude), while the sliders below the flat position are being cut (given less amplitude). Electronically storing these slider positions for recall at a later time would be referred to as creating a Preset.
FIG. 1C illustrates an exemplary Classical music genre EQ setting, with the sliders controlling the ten frequency ranges boosting ranges at the lower and upper ends of the mix or overall frequency range and cutting ranges in the middle of the mix. Similarly, FIG. 1D illustrates an exemplary Hip-Hop music genre EQ setting, with frequency ranges boosted and cut according to how sounds in these ranges particular to Hip-Hop music should be emphasized and deemphasized with respect to sounds in other frequency ranges. FIGS. 1E and 1F illustrate exemplary Metal and Spoken Word genre EQ settings, respectively. Many other genres could also be illustrated, such as Jazz, Pop, and Swing, each with its own arrangement of frequency ranges being boosted, cut or kept flat.
Reproducing sounds, particularly music, with headphones presents unique challenges. Headphone wearers want to listen to different genres of music using a music device of their choice and without having to sacrifice the tonal quality of the sound. The goal is to provide headphones that enable wearers to hear the intended subtleties of different types of music without having to change the type of headphone they are wearing. When listening to Rap music, deep bass sounds should be highlighted. When listening to Classical music, the delicate treble overtones should be crisp and clear. The quality of the sound should not have to be sacrificed just because the headphone being worn is designed for certain genres of music and not others. For this reason, a music genre equalizer selector, placed at a convenient location on the headphone itself, would enable the wearer to switch back and forth between different audio equalizers to enhance the music listening experience.
In the past, headphone developers have created headphones geared towards specific genres. For example, Beats headphones are geared specifically towards Rap and Pop songs with heavy bass. Bose headphones are geared more towards classical music and jazz. The goal of headphone manufacturers has been to exploit niche markets and capitalize on wearers' desires for headphones that suit their specific music genre preferences.
The present headphone design serves wearers whose tastes are not so limited and cover a music library from end to end. Prior attempts at creating a robust aural experience with headphones have thus fallen short because they do not accommodate a full musical spectrum.